Solutions for the peninsula's stormwater.

Less Storm-Related Flooding

The goal is a 20% reduction in the duration, frequency, and severity of flooding caused by moderate to heavy rainstorms along the Septima Clark Parkway and throughout the Spring Street and Fishburne Street drainage basins by summer 2022.

Quick Facts

A quick look at some of the Project numbers.


Tunnel Boring Machine

Phase 3 used two tunnel boring machines to excavate the ground. The larger of the two was 15 feet in diameter and nearly 300 feet long with all of its components.



Phase 3 construction included four shafts up to 30ft in diameter and 180ft deep.



5400ft of 12ft tunnel, 2950ft of 8ft tunnel (which includes the drop shaft tunnels which connect the drop shafts to the tunnels).


Drop Shafts

Eight drop shafts were installed in phase 2 to convey flow from the surface to the deep tunnel. The intent of these is to spin the water into a vortex as it enters the drop shaft to prevent air from entering the tunnel system.


Local Contractors

75 million dollars of work will be awarded to local businesses.



Once complete, the system will be able to move 300,000 gallons per minute from the Charleston peninsula to the Ashley River.